Apparatus for molding



y 1950 L. D. RICHARDSON 2,509,783

APPARATUS FOR MOLDING Filed Oct. 17, 1945 2 Sheets-Sheet l I22 I I12 I v) luvsuron.

LLOYD D. RICHARDSON Jr W 1% y 0, 1950 D. RICHARDSON 2,509,783

APPARATUS FOR MOLDING Filed Oct. 17, 1945 2 sheets-shew; 2

INVENTOR I LLOYD D. RICHARDSON ATTORNEYS BY A Patented Ma 30, 1950 APPARATUS FOR MOLDING Lloyd 1). Richardson, Dayton, Ohio, assignor to H-P-M Development Corporation, Wilmington,

DeL, a corporation of Delaware Application October 17, 1945, Serial No. 622,742

It is still another object to provide an apparatus according to the foregoing objects wherein a single pressing plunger is adapted for actuating the various portions of a multi-part die.

It is still another object to provide an apparatus for forming workpieces from granulated materials which has a plurality of platens for supporting the various parts of a multi-part die and for positively controlling their relative rates of movement.

These and other objects and advantages become more apparent upon reference to the following specification taken together with the ac companying drawings in which:

Figure 1 is a sectional view through the press showing the mechanical disposition of its various parts;

Figure 2 is an elevational view of a press adapted for carrying out the method of this invention;

Figure 3 is a section through one of the operat ing valves of the hydraulic circuit of Figure 2;

Figure 4 is a section through a flow controlling valve of the circuit of Figure 2, and

Figure 5 is a diagram of an electrical circuit iorcontrolling the hydraulic circuit of Figure 2;

General arrangement A press constructed according to this invention comprises, generally, a movable platen which is actuated by a motor, preferably fluid operable.

Opposed to the fixed platen is a bed, and arranged between the bed and movable platen are a plurality of auxiliary platens to which are connected a plurality of plungers. The plungers are reciprocable in cylinders formed in the bed and are permitted to yield at a predetermined rate by providing flow controlling valves to pass the discharge from the said cylinders.

Another auxiliary platen carries a die-cell and is permitted to yield at a predetermined Pressure. 65

4 Claims. (Cl. IS-0.5)

There are provided. stop collars between the various platens so that when the press is in its wide open position the cavity defined by the diecell, and the various plungers therefor, will receive the proper amount of material to form the workpiece. As the pressing operation proceeds, the various parts of the die yield at predetermined speeds so that at the closing or the pressing operation the workpiece is the correct size and shape.

The pressing operation is halted in response to the attainment .of'a predetermined pressure by the pressing plunger or in response to a predetermined position attained thereby. sponse to either of these stimuli, the pressing plunger retracts while the die-cell is moved downwardly to eject the workpiece. Thereafter, the die parts may be returned to their starting peeltion and a new work cycle commenced.

Structural arrangement Referring to Figure 1, the press of this invention will be seen to comprise a movable platen at Ml which is actuated by the double acting plunger [2 which receives fluid from the conduits I4 and IS. The platen Ill carrie the pressing plunger I8 adapted for entering the cavity 20 of a die-cell 22 carried on a platen 24.

Reciprocable in the cavity 20 from the other side thereof is a sleeve 26 carried on a platen 2i! and within the sleeve 26 is a second sleeve 3H carried on'the platen 32. The sleeves 26 and 30 form the bottom for the cavity of the mold while the auxiliary platens which support them con-= trol their relative speed of movement.

The workpiece which is illustrated in Figure l is hollow and there is provided a plunger EM which extends through the die-cavity to form the central aperture in the said workpiece.

The platen 26 is supported on a pair of double acting plungers 36 which are supplied with fluid by the conduits 38 and 40. The platen 28 is supported on a pair or plungers 42 which extend into cylinders in the press bed which are connected to the conduit 44. The platen 32 is likewise supported by the plungers 46 which extend into cylinders in the bed that are connected with the conduit 48.

The plunger 34 is supported like the platen 24 by a double acting plunger 50 which receives fluid from the conduits 52 and 54.

Arranged in association with the platens 24 and 28 are the rods 58 comprising the collars 58 which determine the maximum spacing of the In re-' 3 said platens and the collars 68 which determine the minimum spacing thereof.

Similarly associated with the platens 28 and 32 are the rods 62 having the collars 64 to limit the maximum spacing of the said platens and the collars 66 to limit the minimum spacing thereof.

When the platen 24 is in its uppermost position, it engages the collars 58 and supports the platen 28 while the platen 28 engages the collars 64 and supports the platen 32.

When the platen 24 is in its lowermost position, it engages the collars 68 while the platen 28 engages the collars 66 and so locates the die 22 relative to the sleeves 26 and 38 that a workpiece in the die will be ejected.

In Figure 2 there is illustrated the hydraulic operating circuit for the press. The conduits I4 and I6 of the double acting plunger I2, are connected through a 4-way valve I8 with a supply line I2 and an exhaust line I4. A spring I6 normally urges the valve to supply the conduit l6 and a solenoid at SI is adapted for being energized to bring about the supply of pressure fluid to the conduit I4. A pressure'switch which is normally opened is indicated at T and is adapted for being closed to complete a circuit between the wires 18 and 88 in response to a predetermined pressure on the advancing side of the plunger I2.

The conduits 38 and 48 are connected with a 4-way valve 82 which is normally centered by the springs 84 and 86 and which is adapted for movement into its opposite ends positions by the solenoids S2 and S3. The energization of the former will bring about the supply of pressure fluid from the conduit 88-to the conduit 38, and the energization of the latter bringing about the supply of pressure fluid to the conduit 48. When either conduit is supplied the other is exhausted through the exhaust conduit 98. Connected with the conduit 48 is a relief valve 92 which is operable to support the platens 24, 28 and 32 prior to the pressing cycle. During the pressing operation, the-valve 92 permits fluid to be exhausted from beneath the plungers 36 at a predetermined pressure thus permitting the platen 24 to yield downwardly.

The conduits 52 and 54 are arranged, similarly to the conduits 38 and 48 in association with a 4-way valve 94 which is centered by the springs 96 and 91 and which is operated by the solenoids S4 and S5. A relief valve 96 connects with the conduit 54 for yieldably supporting the plunger 34. The valve 94 is supplied with pressure fluid from a conduit 98 and exhausts into a conduit I88.

The valves 82 and 94 are of the'closed center type and a section through the valve 82 is shown in Figure 3. In this figure it will be noted that when the valve member 83 is in its centered position, the conduits 38 and 48 are closed off to prevent fluid flow therefrom. In order to permit the plungers 36 and the plunger 34 to yield, a check valve 85 connects with the conduit 38 and permits fluid flow thereto while a check valve 95 connects with the conduit 52 and permits fluid flow thereto.

The conduits 44 and 48 are connected,- respectively, with the inlets of the flow controlling valves indicated generally at I82 and I84. These flow controlling valves are by-passed toward the Figure 4 wherein it will be seen to comprise a casing II8 having an inlet compartment H2 and a discharge compartment H4 and a valve member II6 which controls the communication between the said compartments. The valve member comprises the notches H8 which permit relatively free flow between the compartments when the valve member is urged into its upper position by the spring I28, and restrict the flow as the valve member is moved downwardly. For adjusting the position of the valve member H6 in accordance with the rate of fluid flow through the valve in order to maintain the said rate constant, there is provided the adjustable choke valve at I22 whose inlet is connected by a conduit I24 s0 that the pressure therein will act on the upper end of the valve member at I26 and whose outlet is connected by a conduit I28 so that the pressure therein will act on the said valve member at I38. The effective areas at I26 and I38 are equal and the valve member is thus adjusted in accordance with the pressure drop across the choke I22, this drop being a direct measure of the rate of fluid flow.

Referring to Figure 5 an electrical circuit for controlling the actuation of the solenoids of hydraulic valves is shown. In this view LI and L2 are the power lines between which are connected the solenoids SI, S2, S3, S4 and S5 and a contact of solenoid A. SI may be energized by closing the switch I48 which is by-passed by the said conduits by the check valves I86 and I88 respectively.

A section through the valve I82 is shown in blades I42 adapted for being operated into their closed position by their solenoid SI. Energizetion of SI brings about the descent of the plunger I2 and compresses the molding material in the die cavity 28. During the compressing of the said material, the platen 24 yields downwardly against the relief valve 92 and while the platens 28 and 32 yield downwardly at, predetermined rates of speed determined by the settings of their flow controlling valves I82 and I84.

After the plunger I2 has advanced a predetermined amount, it may engage a limit switch LSI to energize" the contactor A which is held by the normally opened blades indicated at A2. Energization of A also opens the normally closed blades at AI which deenergizes SI and permits spring Hi to shift valve "I8 to retract the plunger I2. Simultaneously, S2 and S4 are energized to shift the valves 82 and 94 to direct pressure fluid to the conduits 38 and 52 for moving the plungers 36 and 34 downwardly. The downward movement of plungers 36 brings the platen 24 downwardly and, as pointed out 'hereinbefore, also moves the platens 28 and 32 downwardly and ejects the workpiece from the cavity 28. The downward movement of the plunger 34 withdraws the core from a central cavity of the workpiece and the same may then be removed from the press. 1

After the workpiece is removed, the push button at I44 may be depressed to deenergize A, S2 and S4 while energizing S3 and S5. Energization of S3 and S5 again shifts the valves 82 and 94 and moves the platen 24 and plunger 34 to their uppermost position, the movement of the said platen being effective automatically to position the auxiliary platens 28 and 32. When the parts are in their uppermost position, the push button I44 may be released and thereafter a new cycle maybe commenced.

Optionally, the switch ISI may be replaced by the pressure switch T which is responsive to a predetermined pressure on the advancing side of the plunger l2 for energizing the contact A.

It will be understood that certain modifications could be made in the arrangements shown without departing from the spirit of this invention, for example the platen could be provided with auxiliary platens supported thereon in a manner similar to that in which the auxiliary platens 28 and 32 are supported on the press bed. In this case the pressing plunger would be multipart and each part would have its speed of movement relative to. the other parts hydraulically controlled.

Accordingly, it will be understood that I desire to comprehend within the scope of the claims hereafter appending such modifications and substitution of substantial equivalents as may be necessary to adopt this invention to various conditions and usage.

I claim:

1. In an apparatus for forming work-pieces from granulated materials; a die sleeve; double acting motor means for reciprocating said die sleeve between upper and lower limits; a multipart die bottom; a single acting plunger means connected with each part of said die bottom and adapted for displacing fluid during the pressing cycle; a pressing plunger operable during the pressing cycle for applying pressure to material within the die sleeve and therethrough to said die bottom; variable restrictor valves connected to pass the fluid displaced by said single acting plunger means during the pressing cycle; and fluid operable means responsive to the rate of flow of the fluid displaced by said single acting plungers for adjusting said 'restrictor valves to maintain said rate of flow at a constant rate.

2. In a press; a bed; a first platen; double acting plunger means extending into said bed and supporting said first platen; second and third platens between said bed and said first platen; lost motion connections between said platens whereby said second platen depends from said first and said third platen depends from said second; means for entrapping fluid beneath said plunger and of relieving the fluid at a-predetermined pressure thereby maintaining a substantially constant resistance to movement of said first platen toward said bed; single acting plunger extending into said bed from said second and third platens and operable to displace fluid when said second and third platens move toward said bed; and flow control valves connected to pass the fluid so displaced whereby said second and third platens maintain a constant relative speed during movement toward said bed.

3. In a press; a bed; a plurality of platens over said bed; lost motion connections succelsively most platen for supporting all of said platens in a predetermined position; valve means operable to release fluid from said last mentioned cylinder means at a predetermined pressure therein; and other valve means connected to the others of said cylinder means and operable to permit fluid flow therefrom at a predetermined rate.

4. In a press, a bed, a plurality of platens over said bed; lost motion connections successively suspending said platens in variable spaced rela tion each from the one above; double acting plunger means extending from the uppermost of said platens into said bed; first cylinder means receiving said double acting plunger means; a reversing valve connected to said first cylinder means for reciprocating said double acting plunger means and said uppermost platen and having a neutral position wherein said first cylinder means is closed off; a relief valve connected to the lower side of said first cylinder means for releasing fluid therefrom at a predetermined pressure; other cylinder means in said bed and other plunger means on said other platens extending therein; and valve means connected to said other cylinder means and operable to permit fluid flow therefrom at a predetermined rate.

LLOYD D. RICHARDSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,526,788 Hoffman Feb. 17, 1925 1,679,408 Davis Aug. 7, 1928 1,897,462 Carter Feb. 14, 1933 1,965,670 Schauer July 10, 1934 2,135,803 Dumert Nov. 8, 1938 2,136,240 Ernst Nov. 8, 1938 2,143,429 Auble Jan. 10, 1939 2,253,003 Whipple Aug. 19. 1941 2,259,094 Wellman Oct. 14. 1941 2,318,819 Verson May 11, 1943 2,325,687 Kux Aug. 3, 1943 2,338,491 Cutler Jan. 4, 1944 2,348,197 Ernst et al. May 9, 1944 2,350,971 Pecker et a1. June 6, 1944 2,398,227 Hubbert Apr. 9, 1946 

